1. Field of the Invention
The present invention relates to air filters. More particularly, the present invention relates to air filtering system that are used in industrial operations. The present invention also relates to air filter in which particulate-laden air and/or noxious air is received within the interior of an air filter.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98
Manufacturing processes often generate nauseous and fumes during processing. These fumes are typically unwanted but inherent by-products of the manufacturing process. For example, solvent fumes are typically emitted from baths used for metal parts. The manufacturing of electrical components and electronic circuit boards often creates noxious fumes which arise from the soldering activities of attaching and detaching electrical components in devices such as relays, power supplies, and electronic components to circuit boards. The fumes generated by soldering or desoldering of electrical/electronic components are, at the very least, an irritation to the worker. High concentrations of these fumes may cause illness. Government regulations require removal and venting of the fumes to protect workers.
Particulate-laden air and noxious fumes is generated in a variety of processes. These processes can include soldering, welding, grinding, pharmaceutical powders, and food processing. It is desirable to remove the particulate-laden air or noxious by drawing the air from the area of the particular operation to a remote location. The particles are desirably filtered from the particulate-laden air by using a filtering apparatus.
Devices have been provided for the removal of particles from the particulate-laden air from the workplace. One device uses a vacuum to extract the particulate-laden air from soldering work areas and to pass the particulate-laden air through a filter. The particulate-laden air filter includes a pleated pre-filter for the removal of large particles, a HEPA filter for removing particles down to 0.3 microns, and an activated charcoal filter for removal of volatile components and odors in the particulate-laden air. The vacuum and filter device connects through hoses to articulatable arms that mount adjacent to the work stations. The arms comprise pivotally interconnected tubes with nozzles attached to distal ends. The nozzles are typically elongated tubes having a slit for communicating the air to the filter, although cylindrical nozzles and funnel nozzles are known. The worker that is soldering electronic components moves the articulatable arm to position the nozzle within a proximal area of the solder work. The vacuum apparatus induces a suction through the nozzle for pulling the soldering fumes in the general area of the nozzle into the tube and into the filter apparatus.
Other particulate-laden air removal devices attach a suction nozzle to the soldering iron adjacent to the heating tip. The inlet of the vacuum device is thereby positioned adjacent to the primary source of the solder fumes.
The present inventor is the owner of U.S. Pat. No. 5,843,197, issued on Dec. 1, 1998, for a particulate removal apparatus for use in soldering operations. This patent describes a particulate removal apparatus that has a housing with an inlet opening formed therein and an interior cavity, a filter positioned within the housing for removing particles from air passing therethrough, an impeller positioned within the interior cavity of the housing, and a motor positioned within the interior cavity of the housing and positioned between the impeller and the filter. The impeller has backward-inclined impeller blades. The impeller pulls air through the inlet opening and directs the air toward a wall of the interior cavity. The impeller blades generally surround the interior opening. The filter is a HEPA filter positioned within a framework within the housing. The HEPA filter is arranged in an accordion-style folded configuration within the framework.
It is very important to use the filter so as to remove the particles from the particulate-laden air. Typically, these particles will be embedded within a filter structure. When a significant amount of particles have accumulated within the filter structure, it is necessary to remove and/or clean the filter so that the optimum filtering capacity is achieved. The replacement of the filters often requires a significant amount of downtime and complex cleaning operations. In those circumstances where the filter must be entirely replaced, then the continued replacement of the filters presents a significant cost associated with the particular manufacturing operation.
In the past, reverse pulse cartridge filters have been utilized for the purposes of removing particles from particulate-laden air. Typically these reverse pulse cartridge filters place a filter in a hollow cylinder. An air pipe is in the middle. Compressed air is directed from the interior of the pipe outwardly so as to cause the particles on the exterior of the filter to be discharged within the housing. As such, the discharged particles are removed from the bottom of the filter housing. The particles are blown by a pneumatic pulse from the inside of the filter toward the outside of the filter. Typically, a fixed tubular member is placed within the interior of the filter so as to direct bursts of air in a fixed pattern toward the interior surface of the filter. This type of reverse pulse cartridge filter requires a relatively complex arrangement of solenoids, diaphragms and electronic controls. The system is timed so that after a predetermined period of time, the pulse is directed toward the interior surface of the filter. The continued directing of this pulse toward a specific surface of the filter can cause a deterioration in the fibrous structure of the filter. As such, replacement will be necessary as the filter deteriorates.
In the past, various patents have issued relating to such reverse pulse cartridge filters. For example, U.S. Pat. No. 4,536,200, issued on Aug. 20, 1985 to P. C. Reist, describes a gas filter apparatus and method that utilizes cylindrical pleated paper filters arranged to collect particulates on the interior of the filters from scavenging gas flowed through the filters. The particulates are removed by applying a high pressure gas pulse to an air chamber in a cylindrical housing surrounding each filter in spaced relation which forces the removed particulates axially through an open end of the filter.
U.S. Pat. No. 4,786,293, issued on Nov. 22, 1988 to P. A. Labadie, shows a smart controller for reverse pulse air filters. This control device applies a pressure differential across the air filter. This pressure differential is continuously monitored and compared to a reference set point pressure differential. When the pressure differential across the air filter is greater than or equal to the reference set point pressure differential, a cleaning cycle is initiated. At the end of the cleaning cycle, a new pressure differential across the air filter is measured and compared to the pressure differential before cleaning. If the new pressure differential is lower, it is stored and another cleaning cycle is initiated. This cycle is repeated until the “after” pressure differential is equal to or greater than the “pre-cleaning” pressure differential. At this point, a new reference set point pressure differential is calculated and the initial monitoring cycle is repeated until the pressure differential across the filter becomes equal to or greater than the new reference set point.
U.S. Pat. No. 4,818,261, issued on Apr. 4, 1989 to W. E. Beckon, describes an improved air filter for use in a filtering system which uses reverse air pulse cleaning of a filter medium which is surrounded by and connected in sealed relation to an exterior housing. An energy absorption means is incorporated within the housing in such a manner as to prevent the direct flow of the reverse air pulses during cleaning from directly contacting the seal between the filter medium and the housing. Thereby, the air flow is redirected through the filter medium before reaching the seal.
U.S. Pat. No. 5,147,427, issued on Sep. 15, 1992 to Abbot et al., shows an air filtration system that reduces positive and/or negative resistance by eliminating duct work to and from the to-be-filtered room. The air filtering system forms a common wall with the to-be-filtered room permitting dirty air to move easily and quickly through to the cleaning process. Through the use of vertical baffles and reverse pulsed jets, debris is easily and efficiently collected in drawers or trays.
U.S. Pat. No. 5,395,409, issued on Mar. 7, 1995 to Klimczak et al., discloses a dust collecting apparatus having reverse pulse filter cleaning capability. A plurality of elongated filter elements are periodically cleaned by a reverse pulse cleaning system which directs a reverse pulse of air through the open end of each filter element so as to remove contaminants which have collected on its external surface. The reverse pulse cleaning system has an air delivery pipe above each of the filter elements. Each air delivery pipe includes an air delivery nozzle assembly which includes at least one pair of transverse pipe sections which are transversely aligned and extend in opposite directions from the air delivery pipe so as to define a cross-like configuration. A plurality of apertures are disposed in a linear line along the air delivery pipe. At least one aperture is disposed in each of the transverse pipe sections. By this arrangement, the cross-sectional configuration of the reverse pulse of air entering into the top of each filter element may be predetermined so as to ensure that the pulse properly impacts the interior of the filter element and effectively removes the collected contaminants.
U.S. Patent Publication No. 2004/0261376, published on Dec. 30, 2004 to Morgan et al., teaches a pleated air filter with reverse pulsating air flow cleaning. This air filter assembly has a pleated filter cartridge for filtering out dust from the air. The cartridge is in the form of a receptacle having an open top, a closed bottom and closed sides which run entirely therearound. Pleats are formed in the sides of the cartridge. The pleats are separated from each other by an adhesive bead which may be formed from a hot melt material. In the filtering cycle, air is drawn out by a blower from the inside of the cartridge thereby drawing air from the outsides through the pleated sides which so as to filter out particles. The filtered air is fed from the cartridge to an area requiring clean air. Periodically, the filter is automatically cleaned by compressed pulsating air which is fed to the interior of the cartridge through the pleated sides so as to blow off dirt accumulated on the cartridge.
U.S. Patent Publication No. 2009/0114095, published on May 7, 2009 to Hanson et al., shows a filter cleaning system and method. This filter cleaning system has a baghouse including a tubesheet having a plurality of openings extending therethrough. A plurality of filter cartridges are sealingly mounted to the tubesheet at respective openings. Each filter cartridge has an open end and pleated media for filtering particulates from gas flowing therethrough. The filter cartridge has particulates accumulating on the pleated media. A pulse cleaning system intermittently directs cleaning pulses of air into the open ends of the filter cartridges media at a supply pressure in the range of about 20 p.s.i. to 60 p.s.i. to dislodge accumulated particulates from the pleated media.
It is an object of the present invention to provide an air filtering apparatus that effectively removes particles, odors and irritants from particulate-laden air.
It is another object of the present invention to provide an air filtering system whereby the filters can be quickly cleaned.
It is another object of the present invention to provide an air filtering apparatus which avoids the need for a chassis for the air filter.
It is another object of the present invention to provide an air filtering apparatus which has a minimal footprint and avoids wasted space.
It is another object of the present invention to provide an air filtering apparatus which enhances the flow of air on the interior of the filter so as to enhance the ability of particles within the air to be entrapped in the air filter.
It is another object of the present invention to provide an air filtering apparatus which minimizes the number of components that are used for the filtering of the air.
It is still a further object of the present invention to provide an air filtering apparatus that reduces the costs associated with the filters and the items used for cleaning the filters.
These and other objects and advantages of the present invention will become apparent from a reading of the attached specification and appended claims.